miller/c/mapping/mapper_group_like.c

100 lines
3.4 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lib/mlrutil.h"
#include "containers/sllv.h"
#include "containers/slls.h"
#include "containers/lhmslv.h"
#include "containers/mixutil.h"
#include "mapping/mappers.h"
typedef struct _mapper_group_like_state_t {
// map from list of string to list of record
lhmslv_t* precords_by_key_field_names;
} mapper_group_like_state_t;
static void mapper_group_like_usage(FILE* o, char* argv0, char* verb);
static mapper_t* mapper_group_like_parse_cli(int* pargi, int argc, char** argv,
cli_reader_opts_t* _, cli_writer_opts_t* __);
static mapper_t* mapper_group_like_alloc();
static void mapper_group_like_free(mapper_t* pmapper, context_t* _);
static sllv_t* mapper_group_like_process(lrec_t* pinrec, context_t* pctx, void* pvstate);
// ----------------------------------------------------------------
mapper_setup_t mapper_group_like_setup = {
.verb = "group-like",
.pusage_func = mapper_group_like_usage,
.pparse_func = mapper_group_like_parse_cli,
.ignores_input = FALSE,
};
// ----------------------------------------------------------------
static void mapper_group_like_usage(FILE* o, char* argv0, char* verb) {
fprintf(o, "Usage: %s %s\n", argv0, verb);
fprintf(o, "Outputs records in batches having identical field names.\n");
}
static mapper_t* mapper_group_like_parse_cli(int* pargi, int argc, char** argv,
cli_reader_opts_t* _, cli_writer_opts_t* __)
{
if ((argc - *pargi) < 1) {
mapper_group_like_usage(stderr, argv[0], argv[*pargi]);
return NULL;
}
mapper_t* pmapper = mapper_group_like_alloc();
*pargi += 1;
return pmapper;
}
// ----------------------------------------------------------------
static mapper_t* mapper_group_like_alloc() {
mapper_t* pmapper = mlr_malloc_or_die(sizeof(mapper_t));
mapper_group_like_state_t* pstate = mlr_malloc_or_die(sizeof(mapper_group_like_state_t));
pstate->precords_by_key_field_names = lhmslv_alloc();
pmapper->pvstate = pstate;
pmapper->pprocess_func = mapper_group_like_process;
pmapper->pfree_func = mapper_group_like_free;
return pmapper;
}
static void mapper_group_like_free(mapper_t* pmapper, context_t* _) {
mapper_group_like_state_t* pstate = pmapper->pvstate;
// lhmslv_free will free the hashmap keys; we need to free the void-star hashmap values.
for (lhmslve_t* pa = pstate->precords_by_key_field_names->phead; pa != NULL; pa = pa->pnext) {
sllv_t* plist = pa->pvvalue;
sllv_free(plist);
}
lhmslv_free(pstate->precords_by_key_field_names);
free(pstate);
free(pmapper);
}
// ----------------------------------------------------------------
static sllv_t* mapper_group_like_process(lrec_t* pinrec, context_t* pctx, void* pvstate) {
mapper_group_like_state_t* pstate = pvstate;
if (pinrec != NULL) {
slls_t* pkey_field_names = mlr_reference_keys_from_record(pinrec);
sllv_t* plist = lhmslv_get(pstate->precords_by_key_field_names, pkey_field_names);
if (plist == NULL) {
plist = sllv_alloc();
sllv_append(plist, pinrec);
lhmslv_put(pstate->precords_by_key_field_names, slls_copy(pkey_field_names), plist,
FREE_ENTRY_KEY);
} else {
sllv_append(plist, pinrec);
}
slls_free(pkey_field_names);
return NULL;
} else {
sllv_t* poutput = sllv_alloc();
for (lhmslve_t* pe = pstate->precords_by_key_field_names->phead; pe != NULL; pe = pe->pnext) {
sllv_t* plist = pe->pvvalue;
sllv_transfer(poutput, plist);
}
sllv_append(poutput, NULL);
return poutput;
}
}